SS, it sounds like you have basically already decided to make your Pacific islands worth 3 IPCs each, and you’re just looking for minor advice about whether to move an island over by one sea zone or something like that. As always, if your rule is fun for your playgroup, then, great, have fun! You’re not hurting anyone. That said, I can’t really offer you advice about how to get the balance right on your 3-IPC islands, because I don’t like the overall concept. Your custom map is attractive and colorful and has some territories in just the right places, but I just can’t stomach the idea that the Solomon Islands are somehow worth more money than Colorado and Utah, or that the Caroline Islands are worth more money than Shanghai. I know it’s a game, but that breaks my suspension of disbelief. If the numbers are off by that much then I’d rather be playing Lord of the Rings or Star Wars or something that’s not even pretending to be historical.
The way I see it, the Central Pacific islands are a collection of tiny, barely inhabited rocks with no natural resources beyond a bit of fresh water, limestone, and coconut. In game terms, every central Pacific island put together (Iwo, Wake, Midway, Solomons, Carolines, Marshalls, etc.) is worth less than 1 IPC in terms of what can be generated or extracted from the islands themselves. So the question is, how can we make the islands relevant without blatantly ignoring the islands’ very low economic value?
I see basically three options:
Naval Resupply
Even if the islands didn’t have anything particularly useful on them, they were still a place where boats could dock, anchor, and make repairs or transfer cargo on a surface that wasn’t bobbing and sinking in the waves. 1940s naval technology made it difficult and risky to transfer fuel, personnel, spare parts, etc. on the high seas, so having control of some islands every few hundred miles where you could meet up with friendly ships and take care of logistics provided a real benefit to your overall naval war effort. In Global 1940-type maps, I think this is adequately represented by just putting naval bases on many of the islands. On smaller maps, you might choose to make the island chains worth 1 IPC each to abstractly represent this benefit. You could also have a national objective that provides, e.g., 3 IPCs if you have at least 2 island bases in the Pacific. It’s not clear that you really needed more than 2; having one staging ground to exchange parts and fuel and so on is a really big deal, but by the time you hit staging ground #5 in the same ocean, you start to see sharply diminishing returns.
Unsinkable Carriers
Another major use for the islands was as unsinkable aircraft carriers – numbers are tricky in Axis & Allies because we don’t know how many literal aircraft each “fighter plane” piece represents, but there was a big gap between the capacity of an “average” carrier and an “average” island air base. Truk hosted 300 Japanese aircraft, Rabaul hosted 117 Japanese aircraft, Henderson Field hosted 161 Allied aircraft, and Midway had 127 planes. By contrast, there were only 90 aircraft on the USS Enterprise, 78 aircraft on the USS Lexington, 72 aircraft on the fleet carrier Shokaku, and 30 aircraft on the light carrier Shoho. Officially, this gets picked up in the A&A rules by the fact that you can only put two “planes” on a carrier, but you can put as many “plane” miniatures as you like on an island. In practice, there is very little reason to ever put planes on an island in Axis & Allies because of the strange way that A&A counts aerial movement. Moving out of and then back onto an island counts as 2 movement points, and an airbase only boosts your movement by 1 movement point – so a tiny naval fighter plane sitting on a carrier somehow gets better range than a double-engine fighter plane sitting on a nice long flat runway next to a generous fuel depot, even when the carrier stays put and doesn’t sail toward battle to help pick up its expended fighters. In Global 1940, it’s sometimes helpful that an airbase lets you scramble 3 extra fighters to defend a sea zone, but the airbase is still of limited value, because that defense is static – the fighters landed on the island can’t easily be used to attack enemy targets in any other sea zone, especially if you’re short enough on carriers to want to bother with an airbase scramble. An airbase can help you cheaply maintain a naval stalemate, but it doesn’t give you much of a reason to want to own a chunk of the Pacific in the first place. I think if you wanted this to be the motive to take over Pacific islands, you’d need to fix the movement rules for islands. Maybe just make it so moving from an island to the sea zone that wholly encloses that island (or vice versa) is completely free.
Convoy Raiding Posts
This is really a special case of naval resupply, but part of the idea is that if you can base your subs and destroyers and so on closer to the merchant traffic that they’re preying on or protecting, then you can launch a lot more convoy raids or safely escort a lot more convoys. So, even if the islands themselves are economically worthless, the islands serve as a series of small, conveniently located naval bases that allow you to escort (or sink) ships carrying cargos that are worth a lot of money. The problem with this rationale is that 9 times out of 10, you’d be better off just using a convoy zone! If what you’re trying to represent is the idea that you’ve found a good place to raid merchant traffic, then put a merchant traffic icon on the map. Don’t put an island on the map. An island is not a fleet of merchant marine freighters.